Method for producing a sliding clasp fastener

ABSTRACT

A method is disclosed for producing a sliding clasp fastener, wherein rows of fastener elements are sewn as inter-engaged on a carrier tape. This tape is provided with a seam forming a separation line along which the coupled rows of elements are sewn, and thereafter the seam is dissolved in water thereby separating the tape into identical halves.

United States Patent 91 Terada et al.

[ 1 NOV. 19, 1974 METHOD FOR PRODUCING A SLIDING CLASP FASTENER Inventors: Fumio Terada; Yoshio Matsuda;

Yoshiharu Yamaguchi, all of Uozu,

Japan Assignee: Yoshida Kogyo Kabushiki Kaisha,

Tokyo, Japan Filed: Nov. 26, 1971 Appl. No.: 202,083

Foreign Application Priority Data Dec. 4, 1970 Japan 45-108006 Dec. 4, 1970 Japan 45-108007 US. Cl. 112/265, 24/205 R, 24/205.l .C, 24/205.l6 C, 28/76 T, 66/190, 66/195, 66/202 Int. Cl. A44b 19/40, D05b 3/12 Field of Search 66/86, 190-195,

66/202;24/203.1 C, 205.16 L, 205 R, 205.16 C; 2/266; 112/103, 263; 28/76 T [56] References Cited UNITED STATES PATENTS 2,437,735 3/1948 Getaz 28/76 T UX 3,348,509 10/1967 Degraw 112/265 3,570,482 3/1971 Emoto 3,685,474 8/1972 Frohlich et al. 112/265 3,708,836 1/1973 Frohlich et a1 24/205.l6 C 3,714,683 2/1973 Frohlich et al. 112/265 X 3,757,541 9/1973 Frohlich et al. 66/193 Primary Examiner-Werner H. Schroeder Attorney, Agent, or Firm-Robert E. Burns; Emmanuel J. Lobato; Bruce L. Adams [5 7] ABSTRACT A method is disclosed for producing a sliding clasp fastener, wherein rows of fastener elements are sewn as inter-engaged on a carrier tape. This tape is provided with a seam forming a separation line along which the coupled rows of elements are sewn, and thereafter the seam is dissolved in water thereby separating the tape into identical halves.

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INVENTGR.

METHOD FOR PRODUCING A SLIDING CLASP FASTENER This invention relates to a method of producing a sliding clasp fastener comprising carrier tapes of a knitted structure, and is more particularly directed to the method in which a double row of inter-engaged fastener elements is applied to a warp-knitted tape.

Known methods of this description include bringing two carrier tapes closely together in edge-to-edge abutting relation and laying two inter-engaged element rows on the tapes for sewing longitudinally along their abutted edges. However, there are always encountered some irregularities in the movement of carrier tapes while in transit from the supply roll to the sewing machine and such irregularities are due to irregular rotation of the roll, frictional resistance of the tape guides and other various operating reasons. This would often result in irregularities in the pitch of fastener elements sewn on the tapes. Therefore, with such prior-art methods it is difficult to obtain side fasteners of the desired product quality.

Whereas, it is the primary object of this invention to provide an improved method which permits the production of high-quality sliding clasp fasteners and which will substantially eliminate the above difficulties of prior-art methods.

It is a more specific object of the invention to provide a method of applying two inter-engaged rows of fastener elements onto warp-knitted carrier tapes with sufficient dimensional stability to ensure uniform pitch of the elements when sewn on the tapes. The invention further includes a carrier tape of warp-knitted structure for supporting rows of fastener elements.

These and other objects and features of the invention will appear clear from the detail description which follows with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a warp-knitted carrier tape for attaching fastener elements thereon according to the invention;

FIG. 2 is a perspective view of the tape to which two inter-engaged rows of elements are being sewn;

FIG. 3 is a perspective view of the tape carrying elements thereon and separated into two opposite stringers;

FIG. 4 is a perspective view of a sliding clasp fastener finished in accordance with the invention;

FIG. 5 is a diagrammatic view on enlarged scale of a knit pattern of a portion of the carrier tape embodying the invention;

FIG. 6 is a perspective view of a tape of increased width embodying the invention;

FIG. 7 is a view similar to FIG. 6 but showing the tape separated widthwise into a plurality of carrier tapes of a desired product width similar to the tape shown in FIG. 1; and

FIG. 8 is a diagrammatic view on enlarged scale of a knit pattern of a segment of the tape shown in FIG. 6.

According to the present invention, there is provided a method for producing a sliding clasp fastener comprised of a double carrier tape provided with a watersoluble seam extending longitudinally and centrally thereof, which method essentially comprises the steps of:

a. sewing two inter-engaged rows of fastener elements on the double carrier tape with coupling head portions of said elements held in alignment with the seam;

5 b. dissolving this seam and thus separating the double carrier tape into identical halves along the said seam; and

c. applying a slider and end stops on the thus separated stringer tapes, and cutting the tapes to a desired product length.

Referring now to the drawings and FIG. 1 in particular, there is shown a double carrier tape T made of a warp-knitted fabric and provided with a seam 10 of a water-soluble synthetic fiber such as of polyvinyl alcohol. The seam 10 extends longitudinally and centrally of the carrier tape T and defines a separation line along which the tape is split into identical halves T and T in the manner hereinafter described. There is provided a weft thread 10b of any synthetic fiber which is soluble in contact with water, as shown in FIG. 5, and which constitutes the above-mentioned seam 10.

A double row of elements, i.e., two rows E of fastener elements which have been previously inter-engaged, is applied on the carrier tape T with coupling head portions C of the engaged elements Ea held in alignment with the seam l0 and is thus sewn closely therealong with needles N carrying sewing threads 11 and extending from a sewing machine (not shown) in the manner illustrated in FIG. 2. More specifically, the two interengaged rows of elements are sewn onto the tape T with two parallel lines of stitching S running over leg portions L of the elements and extending in parallel with and on opposite sides of the seam 10.

The double carrier tape T having inter-engaged rows of elements thus sewn thereon is now immersed in wa ter, for example warm water, chemical liquids or the like, whereupon the seam 10 is dissolved so as to separate the tape into identical stringer halves T T now having opposed edges 12 along which the rows of elements are secured, as shown in FIG. 3. The seam 10 may be conveniently dissolved by immersing the tape T in a dying bath or cleaning water bath usually provided in a fastener making factory.

The resulting fastener chain F is now applied with sliders 13 and end stops 14, 14 respectively, at predetermined intervals and cut to a desired product length as illustrated in FIG. 4.

Reference to FIGS. 6, 7 and 8, inclusive, shows a modification of the carrier tape embodying the invention. As shown in FIG. 6, there is provided a relatively wide tape TS of a warp-knitted fabric section which is provided lengthwise with a plurality of alternate first and second groups of water-soluble seams 10 which are dissolvable at two different temperatures. A suitable synthetic fiber may be treated so that it becomes watersoluble at a' temperature of say about 65C for use as a first group of low temperature soluble seams 100. Similarly, a second group of high-temperature soluble seams 10b may be formed by a synthetic fiber which is water-soluble at about 90C. These groups of seams alternate at predetermined intervals on the tape TS, and the first group 10a defines a plurality of separation lines along which the wide tape is first separated into sections Tn by immersion in water at about 65C, each of which sections constitutes a double carrier tape T similar to that which is shown in FIG. 1. Each tape section Tn'contains the second seam 10b which defines a separation line along which the inter-engaged rows of elements are secured to the tape in the manner previously described. Thereafter, the double carrier tape T carrying the inter-engaged element rows is further immersed of carrier tapes being connected together by a lowtemperature soluble connecting thread and the remaining alternate pairs of carrier tapes being connected together by a high-temperature soluble connecting thread; separating said fabric section into pairs of carrier tapes by dissolving said low-temperature soluble connecting thread; then sewing two rows of interengaged fastener elements to each pair of carrier tapes along opposed edges thereof; and then dissolving said high-temperagl resoluble connecting thread from the pairs of carrier tapes to separate each pair into similar halves of a sliding clasp fastener.

2. A method according to claim 1; including applying a slider-and end stops on each pair of separated carrier tapes; and cutting said carrier tapes to a desired product length to form sliding clasp fasteners. 

1. A method for producing sliding clasp fasteners comprising: providing a warp-knitted fabric section composed of a plurality of individual carrier tapes arranged in side-by-side relationship with alternate pairs of carrier tapes being connected together by a low-temperature soluble connecting thread and the remaining alternate pairs of carrier tapes being connected together by a high-temperature soluble connecting thread; separating said fabric section into pairs of carrier tapes by dissolving said low-temperature soluble connecting thread; then sewing two rows of interengaged fastener elements to each pair of carrier tapes along opposed edges thereof; and then dissolving said hithtemperature soluble connecting thread from the pairs of carrier tapes to separate each pair into similar halves of a sliding clasp fastener.
 2. A method according to claim 1; including applying a slider and end stops on each pair of separated carrier tapes; and cutting said carrier tapes to a desired product length to form sliding clasp fasteners. 